The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 04, 2011
Filed:
Apr. 17, 2008
Ronald Pasqualini, Los Altos, CA (US);
Ronald Pasqualini, Los Altos, CA (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
A high voltage CMOS output buffer is constructed from low voltage CMOS transistors. The output buffer employs a series of unique CMOS inverter stages, each of which contains a switched PMOS transistor, one or more voltage drop blocks, and a switched NMOS transistor. The voltage drop blocks are composed of stacked PMOS transistors that are diode-connected—i.e., the PMOS gate terminal is connected to the PMOS drain terminal, and the PMOS body (N-well) terminal is connected to the PMOS source terminal. The diode-connected PMOS transistors reduce the voltage across the transistor gate oxide to a safe value, for all internal PMOS/NMOS transistors inside the CMOS output buffer.